Rapid and cost-effective detection and amplification of nucleic acid is vital for the identification of pathogenic and non-pathogenic agents of biomedical, industrial and research applications as well as other uses in molecular biology and biotechnology. Existing PCR technology, which is typically used in the amplification of DNA, is based on the polymerase chain reaction. Conventionally, a test tube system for DNA replication allows a “target” DNA sequence to be selectively amplified or enriched several-fold in several hours. During such conventional PCR, high temperature is used to separate the DNA molecules into single strands (typically in one to several minutes at 94-96° C.), and synthetic sequences of single-stranded DNA (typically 20-30 nucleotides) serve as primers. Typically, two different primer sequences are used to bracket the target region to be amplified. The primer anneals to the DNA by way of hydrogen bonds. This annealing step typically occurs over about one to several minutes at about 50-65° C. After primer hybridization, the DNA is heated from typically about one to several minutes at about 72° C. in the presence of a polymerase, during which time the polymerase binds and extends a complementary DNA strand from each primer.
Since PCR was first conceived, all known techniques and equipment have required heating elements and temperature controls to thermally treat DNA in each step of the process. However, such techniques and equipment require considerable operating time and heating temperatures, which lead to DNA loss or damage, potential increases of error, and considerable operating and maintenance time and cost. Accordingly, it can be seen that needs exist for improvements in PCR techniques and equipment. The methods and devices described herein address these needs.